As is known, many situations exist in which medical personnel entrusted with the care of patients, are exposed to contagious environments derived from the fact that said personnel may accidentally jab themselves, due to the undue care or any other circumstance, with the needle of a syringe, once used to administer a specific drug to any patient under their care. This fact becomes especially relevant when said patients suffer from severe diseases, such as hepatitis C or AIDS.
With the purpose of preventing situations of the type mentioned above, the present invention has developed a system, whose activation is produced automatically and without need of any intervention or manipulation, providing protection of the needle just used to inject the drug.
The system of the invention is based on the use of some needle protection devices, which may be activated when the injection of the drug in question is being terminated, that is when the syringe stopper is about to reach the end of its run, when release devices of the protection devices are activated and which extend to cover the needle along its entire length and being designed such that once extended they cannot retract, hence assuring that the end of the needle is no longer uncovered and within reach of the user. The mentioned means of needle protection have been designed as from one or more individual components, suitably arranged around the syringe body or nozzle before being activated, concentrically with the latter and capable of being automatically extended, preferably by means of a spring, when the mentioned release is produced.
According to the invention, the system provides a set of possibilities, such as:
1) At its upper external end, where the injecting needle is adjusted, the nozzle incorporates around itself some cones and/or tumblers of a conical and/or cylindrical shape, which are interlocked and/or coupled, one inside the other forming a sort of cylindrical, conical or extended tube and depending on the measurement and quantity of cones and/or tumblers, the length of the cylindrical tube may be extended or shortened according to the size and length of the injecting needle.
2) The needle may be both fitted inside and/or outside the syringe.
3) The needle is fitted in the upper end of the nozzle, independently through the inside or outside, in turn around the needle and/or the part where it is coupled, there is a spring, which is fastened and/or fitted over a lengthened cylindrical surface which, in turn, may support the injecting needle.
When the needle is fitted inside the nozzle, the spring and its corresponding parts may be directly fitted over the needle.
4) The tumblers and/or cones are designed such that they perfectly fit inside each other, but at their ends, both upper and lower, they have a hook shape, such that on unfolding they are fastened inside each other, being it possible to pile an unspecified quantity of them to obtain any measurement and/or length.
5) The first tumbler and/or cone, located at the outside end and/or outside part of all of them, will be fitted to the nozzle to hide and fasten the rest of the tumblers, being it possible to dismantle and/or fix the combination over the syringe.
The combination of tumblers and/or cones may be manufactured separately, to fix them at a later date over any syringe, making small changes to said syringe but only in the extreme neck where the needle is usually adjusted and adding the trunco-conical protrusion to the piston so it may activate the mechanism.
6) The last tumbler, internally nearest to the injecting needle, will incorporate a support and/or washer with the purpose of fastening the spring and keeping it compressed. It will also include some parts to fasten to the syringe and hence overcome the pressure exerted over it by the spring, when in its initial position, before using the syringe.
Once the mechanism, has been activated automatically by the pushing motion applied manually over the stopper and piston, for the trunco-conical protrusion to activate the parts fastening the spring and, in turn, the tumbler and hence released, it is then that the spring will push the last tumbler upwards dragging the rest.
7) All the tumblers will be embedded in each other, one fitting in the other in the initial position. For this to occur, the first tumbler (outside) will be fixed to the nozzle and the rest inside and the last tumbler (nearest to the needle) will keep the spring around the upper neck and/or injecting needle compressed and in turn will remain fastened to the nozzle by some parts designed for such a purpose. To overcome the pressure exerted by the compressed spring, these parts will be in contact with other parts fitted in the upper inside part of the nozzle, being those which will finally release the first cone/tumbler permitting the spring to expand and pushing the tumbler and the rest of them upwards, permitting their function to be satisfied, namely that of protecting the needle from possible undesired jabs.
8) To prevent the mechanism from accidental activation before using the syringe, there are several safety devices.
According to the invention, an alternative method to carry out the preferred embodiment has been foreseen involving the use of a component configured like a bellows, which is fastened at its proximal end to the syringe nozzle, whilst at its distal end it incorporates a component like a tumbler provided with consistent retention devices, preferably, in short sections directed orthogonally towards the inside, related to flexible sections of the inside wall of the mentioned tumbler component and opposite at least a pair of mobile release parts, crossing the nozzle wall and susceptible to be pushed from inside by an extreme, conical section of a part interlocked to the stopper-piston combination and displaced with it. When said release occurs, the bellows is pushed forwards in the direction of the needle, due to the recovery of a spring which in the rest position is compressed, such that the length of the part in the bellows mode, which is greater than the hypodermic needle, permits the mentioned needle to recover in its total length. Moreover, the extreme tumbler part related to said bellows has a semi-ovoidal wall directed towards the inside space and divided in sections by means of appropriate cuts in a longitudinal direction. This wall is of elastic material, such as plastic or any other suitable one, such that when the bellows is stretched and the tumbler displaced forwards together with it, the elastic recovery of the mentioned wall material makes the different sections tend to approach each other, matching to form an extreme tip opposite the tip of the hypodermic needle itself, which evidently prevents the accidental or provoked return of the tumbler in the direction opposite to the extension in which it was displaced previously.